1. Field of the Invention
The invention relates to an improved rod bearing, and, more particularly, to an improved bearing for journaling a playing figure actuation rod in a fussball game table.
2. History of the Prior Art
This invention is directed to a bearing member for a fussball (also known as table soccer) game table generally of the type shown in U.S. Pat. No. 3,926,432. Typically, fussball game tables include a rectangular, box-like playing area supported on four legs. A plurality of axially slideable and rotatable rods are mounted on bearings and extend transversely of the playing area. The actuation rods each mount a plurality of playing figures which are arranged above the playing surface of the table in preselected formations. A light ball is placed on the playing surface and propelled by sharply rotating the actuating rods with their respective bearings, so that the foot of the playing figure strikes the ball and propels it along the playing surface toward one of the two goals located at opposite end walls of the table.
The rod bearings on prior art fussball tables are generally the most difficult portions of the table to service and maintain. In operation in a vending machine environment, the playing figure actuation rods gather dust from the environment and dirt and other soil from handling during operation. Because the actuation rods are continually being rapidly moved in an axial manner back and forth within the rod bearings dirt, debris and other matter deposited on the rods is scraped therefrom by the edges of the bearings. Consequently, the rod bearings must be removed and the bearing surfaces cleaned frequently to ensure smooth, rapid operation of the playing figure actuation rods.
Certain techniques for minimizing the maintenance required for fussball table rod bearings have been utilized in the past. For example, rod bearings have been constructed to include a circumferentially extending channel around the outside of the bearing so as to define a knife edge trough contiguous to the rod receiving aperture. This knife edge is intended to shave foreign material from the rod and collects it in the trough as the rod is slid back and forth within the bearing. This structure is intended to simplify maintenance by enabling one to merely clean the troughs periodically and avoid the time consuming removal of the bearings from the machine in order to effectuate cleaning. However, such bearing structures leave much to be desired in that a great deal of foreign matter is still collected on the interior bearing surface and may result in binding of the rods unless the bearings are periodically removed and the interior bearing surface thoroughly cleaned.
Prior art separable rod bearing structures overcome some of the maintenance difficulties such as ease of removal for cleaning. However, certain major problems are still present. For example, a rod moving in a prior art bearing must be lubricated frequently in order to maintain as low function as possible. In addition, the lubricant, typically a silicone spray material, builds up deposits on the rod which must be removed. The lubricant also attracts and holds dust and dirt to the rod further complicating rod bearing maintenance. The structure of the separable rod bearing of the present invention includes an anti-friction ring which virtually eliminates a need for lubricant greatly simplifying table soccer maintenance procedures.
Fussball rod bearings also receive a type of loading which is often damaging to the actuation rods. Game players generally bear down on the actuation rods with large portions of their weight before and during movement of the playing figure. This weighting causes the rod to bend, or flex, above the bearing surface. Many prior art bearings incorporate a circumferential ridge, or narrow land, within the bearing which effectively functions as a fulcrum or point of bending during weighting. The result of unlimited fulcrum bending is plastic deformation of the actuation rod, which commonly occurs in the vicinity of the nearest aperture formed in the rod. The playing figures are secured to the actuation rods through such apertures. These apertures comprise the weakest sections of the actuation rods subjected to bending loads and often exhibit shear rupture during heavy loading. The rod bearing of the present invention overcomes this problem by providing a stop element outwardly of the anti-friction bearing ring which prevents flexure of the rod across the bearing ring beyond the elastic limit of the nearest aperture.